Climate change

Barranco, the smallest district of Metropolitan Lima, is suffering from serious environmental problems that are affecting its inhabitants. Environmental degradation is a consequence of the increase in large buildings (real estate boom), which reduces green space areas and causes a deficit of vegetation in the district. Additionally, there are high levels of air pollution due to car traffic, which has been accentuated by the lack of green areas in the area, which affects the environmental quality and the population's quality of life (1).
Additionally, the district doesn't have more free public areas where new green areas can be created. Due to these combined pressures, the local government has looked for alternatives, considering private areas, which have a high potential to implement green roofs and vertical gardens, which can contribute to face Climate Change as a mitigation strategy and improve the quality of life (1). The Green Roofs and Green Walls strategy is proposed to build citizen culture, nature appreciation, landscape, and ecosystems (2, 3). The aim is, therefore, to encourage the inhabitants of the district to progressively install green roofs and walls, employing an economic incentive in the taxes paid to maintain public green areas (4).
The programme is oriented to generate environmental benefits such as the reduction of air pollution, acoustic insulation, thermal comfort, and increase of green areas (m2) per inhabitant, and social benefits such as the improvement of the living conditions and health of the inhabitants of the district (1, 3), the promotion of social relations (1), the aesthetic improvement of the city, and the possibility of producing food for self-consumption, as there is support in the implementation of hydroponic systems in the green walls and roofs (1, 3). Its implementation focuses on new, under construction or existing residential, commercial, office or lodging buildings (3).

The municipal real estate company Higab partnered with The Foodprint Lab Architects, an architecture firm specialising in food system design, in a three-year pilot project to create urban farms in three of their properties in Gothenburg. The Foodprint Lab designed the urban farms based on the conditions of each property and connected Higab with potential farmers. The urban farms are located at Slakthuset (an old industrial area), Kviberg (by an empty building undergoing renovation) and Musikens hus (an old building used for music events and a restaurant). The farms are established in unused, mostly grey areas such as parking lots. In all sites, the farming is run by local farming associations; some sell vegetables on site and in Kviberg, there has also been a commercial production of vegetables. Sustainable food production, entrepreneurship opportunities, a nicer and safer environment, and the promotion of biodiversity are highlighted as benefits of the project. In total, about 50 different plant species are found across the locations. The establishment of the urban farms was part of the Grow Gothenburg project within the Sharing Cities Sweden program, which provided some of the funding [Ref. 1-5, 7].

Civic Space Park, located in the heart of Phoenix, Arizona, is a notable example of urban design aimed at addressing the region’s increasing urban heat. In Phoenix, rising temperatures affect health, safety, comfort, and economic growth, and this impact is expected to worsen over time. In response, the park was developed to transform an underused site into a vibrant public space that prioritizes community engagement, sustainability, and urban revitalization.
The project was realized through a public-private partnership between the City of Phoenix and Arizona State University, with strong community involvement shaping its development. This collaboration led to the “Urban Weave” concept, a design that embodies the identity and values of the local community.
Civic Space Park was designed with several goals in mind. Increasing the tree canopy was essential to help reduce the urban heat island effect and improve air quality. Creating a welcoming area for social interaction, recreation, and relaxation was equally important to enhance community well-being. Water conservation was also prioritized, achieved through innovative stormwater management techniques such as permeable paving and underground infiltration. The park incorporates renewable energy generation as well, with on-site solar power helping to reduce energy consumption.
One of the park’s unique features is its extensive use of pervious concrete paving, designed to allow stormwater to permeate directly into the subsurface. However, during installation, it became clear that placing the material over highly compacted soil limited water infiltration. To improve its effectiveness, future designs could include a plastic vapor barrier beneath the permeable paving to capture water and direct it to planting beds. This adjustment would enable the paving to act as a collection and storage system, gradually releasing water into the surrounding vegetation.
(1-6)

As an industrial city under climate change, Birmingham has been confronted with multiple environmental risks such as air pollution, fluctuating precipitation and flooding (Ref 3). The Big City Plan is a 20-year city center regeneration plan to support Birmingham’s sustainable transformation, where the delivery of the Eastside City Park was prioritized (Ref 1, 2). Completed and opened to public in 2013, this first new park in Birmingham for 130 years is a linear site which connects the city center along the frontage of Millennium Point eastwards towards the Digbeth canal. (Ref 1, 4, 5). Providing 2.73 ha of urban green spaces, the multi-award winning development features more than 300 trees, a 110 meter canal water feature and a public square with 21 jet fountains, and offers “a moment of green in a journey through the city” (Ref 1, 6).

The project features a vertical garden, or "living wall," on the facade of a residential building in Berlin’s Kreuzberg district. Constructed in 2016, the building replaced a WWII-damaged plot situated between two existing structures. With a strong emphasis on sustainability, the project minimizes its ecological footprint in various ways. The 660-square-meter plot retained original elements of the location’s history: the two surviving sections along Glogauer and Reichenberger Strasse were restored after the war, while the rubble from the destroyed corner was used to fill in the basement. This approach allowed the new construction to be built over the original foundations, preserving historical integrity while reducing construction costs and material use.
At the core of the building’s design is a green agenda, embodied in the vertical garden that helps absorb noise and pollution from the bustling street below, improving air quality for residents and passersby. The selection of winter-hardy plants ensures that the facade remains green year-round, while also cooling the surrounding area and mitigating the urban heat effect, which is especially valuable in densely populated neighborhoods. The greenery contributes to the local microclimate, providing both environmental and aesthetic benefits.
For residents, the garden is made accessible through rectangular box balconies that project from the green wall, allowing them to engage closely with the plants and enjoy the immersive garden atmosphere. The plants grow on a support structure that is securely anchored in the brickwork, receiving water and nutrients through an integrated, precision-controlled irrigation and fertilization system. Maintenance of the plants occurs twice a year, with new additions planted each spring to maintain the garden’s health and visual appeal.
The building itself, privately owned, contains a mix of holiday rentals and residential apartments. Architect Sarah Revière designed the project. (1-6)

Ireland’s native trees have developed over thousands of years, forming a vibrant ecosystem alongside surrounding plants, animals, fungi, and microbes. These trees provide critical habitats for plants and wildlife, offering essential food and shelter while producing oxygen vital to animals and humans alike. Historically, native trees supplied early Irish communities with fuel, food, shelter, and building materials. Today, they play a modern role in filtering dust, reducing pollution, and enriching urban spaces.
To highlight these benefits in Dublin, the Native Tree Trail in St. Anne's Park was created by DCC Parks and Landscape Services in 2008. This trail, featuring 15 different types of native trees, invites visitors to explore and appreciate the natural and cultural heritage of Ireland's native trees, underscoring the value of green spaces for both biodiversity and community well-being.
Strategic tree placement contributes to Dublin’s sustainability by reducing soil erosion, sequestering carbon, and mitigating urban heat. A green city is a healthy city, and preserving open spaces enhances its appeal as a place to live, work, and visit. The trail also plays an essential role in environmental education and community engagement. Over the years, St. Anne's Park has hosted multiple tree-planting events, including a 2019 collaboration with local schools for National Tree Week and National Tree Day, in partnership with the Tree Council of Ireland. The NGO has also offered family-friendly guided walks along the trail, helping to instill an appreciation for nature in visitors of all ages (1, 2, 3, 4, 5, p.93).

The Cinturón Verde de Independencia initiative is a pilot intervention that seeks to plant an urban forest in the lower middle-class district of Independencia (1) in the northern part of the urban territory (3). Here, 19% of the population lives in high-risk conditions, settled on steep slopes, and threatened by landslides (3).
It is part of a broader planning strategy that involves proposals engaging different levels of government (4). This project seeks to afforest the district's hillsides to improve the environment, reduce air pollution, improve the quality of life of its inhabitants, manage waste, regulate shade, control erosion, increase wild biodiversity, and provide spaces for environmental education (2). The Independence Green Belt is linked to a wide range of plans, projects, and decrees that have been developed by actors at different levels of government since 2016 (4). It works hand in hand with the EBA Lomas programme and seeks to create a green belt along the Lomas-city interface, which acts as a buffer zone for this sensitive ecosystem and creates a protective boundary against the expansion of irregular human settlements while providing a space for environmental awareness (2).
This program was developed by a consortium of multiple private, public, national, and international parties with strong community support (3). In two phases, an urban forest park of 4,800 of native trees irrigated with treated wastewater has been planted. During the first phase, PREDES planted 3,300 trees with USAID support in 2015, and another 1,500 were recently planted by PERIFERIA (consultants) (3).
The Independencia Green Belt occupies the hill areas of the district of the same name and relates to a possible metropolitan-scale buffer belt.
Its boundaries take advantage of the seven Sustainable Ecotourism Forest Parks (PFES) in the District Municipality of Independencia (MDI), as well as 115 hectares of the Amancaes Lomas (4). It aims to conserve 400 hectares (4).

The Heat Action Planning project in the Lindo Park-Roesley Park Neighborhood in Phoenix, Arizona, specifically addresses the heat-related challenges residents face in this area. Phoenix is particularly vulnerable to extreme heat events, and this project aims to provide both mitigation and adaptation strategies to reduce the direct impacts of heat and help residents cope more effectively with these conditions. As part of the city’s broader Heat Action Plan, the Lindo Park-Roesley Park initiative is one of three target areas, including Edison-Eastlake, just east of downtown Phoenix, and the Water Tower Improvement District in the City of Mesa. The project focuses on heat hazards such as extreme temperature events and the urban heat island effect, which disproportionately affect vulnerable populations.
This project is a collaborative effort, uniting a range of stakeholders including The Nature Conservancy, Maricopa County Department of Public Health, the Central Arizona Conservation Alliance, the Urban Resilience to Extremes Sustainability Research Network, Arizona State University’s Urban Climate Research Center, and the local residents. Together, these partners are working to develop comprehensive heat mitigation and adaptation strategies that address social equity and strengthen community engagement. Furthermore, the Heat Action Planning process was designed to serve as a model for future heat resilience efforts and create a local, contextual, and culturally appropriate vision of a safer, healthier future. The iterative planning and engagement method used by the project team strengthened relationships within and between
neighborhoods, community-based organizations, decision-makers, and the core team, and it combined storytelling wisdom and scientific evidence to better understand current and future challenges residents face during extreme heat events.The ultimate aim is to foster a more resilient and equitable neighborhood (1-7).

Phoenix faces substantial challenges related to extreme heat, air quality, and social inequity (1-11). The Phoenix Tree Equity Pledge, launched in 2021, is a comprehensive city-wide initiative focused on addressing urban tree inequity and reducing the effects of extreme heat, especially in communities most vulnerable to these conditions (1-12). Partnering with American Forests, the country’s oldest conservation nonprofit, the initiative aims to achieve “tree equity” by 2030, ensuring all neighborhoods receive the benefits trees offer (1).
To reach this goal, the city will focus on enhancing tree coverage in underserved neighborhoods through the development of a Residential Tree Equity Accelerator, which plans to plant 20,000 trees across 25 neighborhoods by 2030 (1-12). By utilizing the Tree Equity Score developed by American Forests, the city can monitor progress, identify areas of need, and measure the impact of these projects (2-4, 9, 11).
To foster public engagement, the initiative will collaborate with residents, businesses, and local organizations to support tree-related projects, raise awareness of the benefits of trees, and promote tree stewardship (1, 4, 15). Additionally, the project aims to create green opportunities within the community by establishing supportive policies and regulations for tree planting and care and by creating pathways to green jobs (1, 7-9, 13-14). Recognizing that heat affects communities unequally, the Tree Equity Pledge seeks to increase canopy coverage in targeted neighborhoods, improving air quality, reducing the urban heat island effect, and enhancing overall community health (1, 7-9, 13-14).

The Dublin Urban Rivers LIFE (DURL) project incorporates two interconnected wetlands in Griffeen Park as part of its broader initiative to improve water quality, natural water management and aquatic biodiversity in urban areas. These wetlands were specifically designed as a natural sewage system to treat wastewater from the surrounding areas, addressing a significant environmental issue known as "domestic misconnection." Domestic misconnection occurs when household appliances, such as washing machines, dishwashers, and kitchen sinks, are incorrectly linked to surface water drains rather than the sewage system. This leads to untreated wastewater being directly discharged into local waterways, contributing to contamination.
In the River Griffeen catchment, which includes approximately 12,000 dwellings and associated infrastructure, domestic misconnections are a considerable threat to water quality. The DURL project focuses on identifying and rectifying these misconnected appliances to ensure that wastewater is properly treated before entering the river. This process will not only improve water quality but will also provide flood alleviation and support healthier aquatic ecosystems in the area.
The project is aligned with broader environmental policies, including the River Basin Management Plan 2022-2027, the Water Framework Directive, the Climate Change Action Plan, the Floods Directive, and the draft Biodiversity Plan. One of the key strategies is to use a Geographic Information System (GIS) to streamline inspections for domestic misconnections, making the process faster and more cost-effective.
The constructed wetlands in Griffeen Park, with a standing water depth of approximately 30 cm, are planted with a variety of native Irish species. These wetlands offer a natural, sustainable solution to wastewater treatment, with the potential for similar applications across Europe. (Ref. 2, 4)